Torsion Wing Probe Assembly
AssigneeBruke Nano, Inc.
InventorsShuiqing Hu, Martin Wagner, Weijie Wang, Chanmin Su
Life of this patent
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Abstract
A torsional probe for a metrology instrument includes a cantilever coupled to a support structure via a torsion bar. The cantilever, support structure, and arms of torsion bar have substantially the same thickness.
Claims17
A torsion wing probe assembly comprising:
- a base;
- and
- a probe extending from the base, the probe including,
- a support structure;
- a cantilever having opposed ends, a first free end supporting a tip, and a second free end;
- a torsion bar including a pair of torsion arms coupling the cantilever to the support structure;
- and
- wherein thicknesses of the support structure, the cantilever and the torsion bars are the same.
The torsion wing probe assembly of statement 1, wherein the thickness is less than 5 μm.
The torsion wing probe assembly of statement 1, wherein a ratio of the natural resonant frequency to the spring constant (f0/k) of the probe is at least three (3) times greater than the f0/k of a diving board cantilever having one end fixed to a diving board base.
The torsion wing probe assembly of statement 1, wherein a stiffness of the support structure is at least ten times greater than the stiffness of the torsion arms.
The torsion wing probe assembly of statement 1, wherein the probe, support structure and cantilever are silicon nitride.
The torsion wing probe assembly of statement 1, wherein the depositing step is LPCVD.
The torsion wing probe assembly of statement 1, wherein the cantilever includes first and second portions on opposites sides of the torsion arms, wherein the surface area of the first portion is equal to the surface area of the second portion.
The torsion wing probe assembly of statement 1, wherein the substrate is a silicon wafer.
The torsion wing probe assembly of statement 1, wherein the tip material is silicon.
A method of operating an AFM to measure photothermal induced surface displacement of a sample, the method comprising the steps of:
- providing a torsion wing probe having a support structure, a cantilever supporting a tip and a torsion bar including torsion arms coupling the cantilever to the support structure;
- driving the probe in to oscillation in an AFM mode of operation;
- directing IR radiation toward a surface of the sample at about a location of the tip causing displacement of the surface and driving the torsion bar in to resonance;
- measuring the displacement based on deflection of the probe in response to the directing step.
The method of statement 11, wherein the AFM mode is PFT mode.
The method of statement 11, wherein the torsion wing probe has a homogeneous thickness.
The method of statement 11, wherein the IR radiation is mid-IR radiation.
An AFM comprising:
- a torsion wing probe that interacts with a sample;
- an optical deflection detection apparatus for measuring probe deflection;
- and
- wherein the optical deflection detection apparatus includes a laser and a detector, the laser directing radiation toward the probe and the probe reflects the radiation toward the detector, and wherein sensitivity of the deflection measurement is independent of where the radiation contacts the probe.
The AFM of statement 15, wherein the torsion wing probe assembly includes,
- a base;
- and
- a probe extending from the base, the probe including,
- a support structure;
- a cantilever having opposed ends, a first free end supporting a tip, and a second free end;
- a pair of torsion arms coupling the cantilever to the support structure;
- and
- wherein the support structure, the cantilever and the torsion bars have equal thicknesses.
The AFM of statement 16, wherein the tip is made of silicon, and the cantilever is made of silicon nitride.
The method of statement 16, wherein the thickness is less than 5 μm.
Dependencies are inferred from the claim text.